1. Field of the Invention
The present invention relates generally to a modular trench drainage system including a base member and a removable grate cover, and especially, such a system that reduces the installation time of the drainage system and accommodates expansion and/or contraction of a surrounding natural surface or pavement area.
2. Description of the Related Art
Conventional trench drains are typically recessed into a natural surface or pavement area composed of a material such as concrete and the like for catching fluid runoff and preventing entry of undesirable debris such as leaves and branches into the drain. These drains comprise generally a base frame member and a grate cover which is positioned on and received by the base member in order to cover an exposed opening at the upper surface of the base frame member. The base frame member includes a lower wall and a pair of sidewalls extending from the lower wall to define a fluid conduit. Typically, upper end surfaces of each sidewall are mitered in order to provide a support surface for the grate cover. The grate cover includes a lower surface which rests on the base frame member conduit and an upper surface that serves as a support surface for vehicular and/or pedestrian traffic. The upper surface of the grate cover is provided with a plurality of openings along its length to permit the entry of fluid runoff into the base frame member.
A disadvantage of conventional trench drain systems is the potential safety hazard resulting from the lack of a connection, removable or otherwise, between the grate cover and the base frame member. Because the grate cover is unattached to the base frame member, unintentional, unauthorized or accidental removal of the top cover is likely, and thus, could result in injury to a pedestrian or damage to a vehicle.
Another disadvantage of conventional trench drain systems is the difficulty and time involved with the installation and/or removal the grate cover from the base frame member. This is due to the use of complicated attachments schemes for establishing a secure connection between the grate cover and the base frame member.
Yet another disadvantage of conventional trench drain systems is the inability of removing the grate cover from the base frame member in order to perform maintenance on the system. For example, some trench drain systems are characterized in a permanent, unitary attachment between the grate cover and base frame member, thereby preventing the removal of the grate cover. Because quick and easy access to the interior of the base frame member cannot be accomplished by merely removing the grate cover therefrom, the entire system must be removed in order to perform routine maintenance such as removing debris and sediment from the interior of the base frame member.
Still another disadvantage associated with conventional trench drain systems is the instability of the connection between the grate cover and base frame member when the natural surface or pavement area in which the trench drain is inserted expands and/or contracts. For example, during warmer months, the natural surface or pavement area surrounding the sidewalls of the base frame member become heated, thereby expanding and exerting an inward force or pressure on the sidewalls. This force causes the sidewalls to deflect laterally inwardly, and thus, results in their original shape becoming distorted.
The distortion of the sidewalls adversely effects the connection between the grate cover and the base frame member in at least two ways. First, the distortion of the sidewalls may cause a loss in connection between the grate cover and the base frame member. Such a loss in connection diminishes the ability of the trench drain to prevent unwanted debris from entering therein and may also cause potential hazards to both pedestrians and/or vehicular traffic. Secondly, the distortion of the sidewalls may place the grate cover out of alignment with the base frame member. In other words, the distortion of the sidewalls may cause bulging of the grate cover, thereby resulting in difficulty in or even preventing the re-establishment of the connection between the grate cover and the base frame member even if an intentional, unintentional, unauthorized or accidental removal of the grate cover from the base frame member has occurred. This becomes economically disadvantageous since the trench drain system must be removed and replaced with a new trench drain system.
It is known, for example, as disclosed in U.S. Pat. No. 4,490,067, to provide a modular drain system that functions as an expansion joint to accommodate expansions and contractions in concrete slabs into which the drain is embedded. This system, however, includes an integrated design characterized by an upper portion which functions as a grate cover and which is permanently attached to a lower portion which function as a base frame member for accommodating entry and removal of a fluid. Accordingly, performing routine maintenance such as cleaning of the system is difficult since the entire drain system must be replaced.
Accordingly, it is an object of the present invention to overcome the foregoing disadvantages in providing a modular trench drain system that reduces the time involved for installation and removal of the system.
It is another object of the present invention to provide such a system having a base conduit and a detachable grate that allows the facilitation of routine maintenance.
It is a further object of the present invention to provide such a system having a pivotal connection between the base conduit and the grate cover that facilitates the removal of the grate cover from the base conduit in a simple, yet expedient manner.
It is a still another object of the present invention to provide such a system which is capable of withstanding distortion of the base conduit without losing the connection between the grate cover and the base conduit.
It is yet a further object of the present invention to provide such a system having a robust connection between the grate cover and the base conduit even in cases which the base conduit becomes distorted due to the expansion and/or contraction of the surrounding natural surface or pavement area.
It is still a further object of the present invention to provide such a system having a structural interconnection between the grate member and the base conduit that facilitates reconnection of the grate cover to the base conduit even in cases in which the base conduit becomes distorted due to the expansion and/or contraction of the surrounding natural surface or pavement area.
It is yet another object of the present invention to provide such a system that permits realignment between the grate cover and the base conduit even in cases in which the base conduit becomes distorted due to the expansion and/or contraction of the surrounding natural surface or pavement area.
Yet and still another object of the present invention is to provide such a system having a grate cover that is mechanically fastened to the base conduit to prevent unintentional, accidental or unauthorized open drain conditions.
These, as well as other objects, are achieved in accordance with an exemplary embodiment of the present invention in which a modular trench drain system is provided for placement into a natural surface or pavement area such as concrete or the like. The system includes a base conduit and a grate cover pivotably connected to the base conduit for movement between an open position exposing an upper surface of the base conduit and a closed position covering the exposed upper surface of the base conduit while permitting fluid communication between the exterior of the cover and the base conduit.
The base conduit includes a support surface for supporting and anchoring the base conduit in a trench formed in the natural surface or pavement area, an interior lower wall, and a pair of opposing sidewalls extending upwardly from the lower wall to define a channel that permits the collection and flow of a liquid such as water and the like. The support surface includes a pair of flange members which outwardly extend perpendicularly with respect to the sidewalls to allow the base conduit to be secured to the natural surface or pavement area via nails, bolts or the like, and thereby prevents movement of the base conduit relative to the natural surface or pavement area.
The grate cover includes a substantially rectangular body including a lower surface that faces into the channel of the base conduit and an upper surface that is coplanar with the contiguous surface of the natural surface or pavement area. The grate cover body is provided with a plurality of spaced openings that extend from the upper surface to the lower surface to permit communication between the exterior and the channel for admitting fluids such as water or the like into the channel.
The system further includes a coupling mechanism for pivotably securing or connecting the grate cover to the conduit base when the grate cover is in the closed position. The coupling mechanism includes a first coupling member formed at the upper end of the sidewall and a second coupling member formed on the lower surface of the grate cover body. The second coupling member is adapted to form a pivotal locking engagement with the first coupling member when the grate cover is in the closed position. The first coupling member includes an elongated flange that projects substantially perpendicularly from the sidewall and into the channel. The second coupling member includes an elongated shaft and a shoulder that projects substantially perpendicularly from the shaft. The shoulder is spaced from the lower surface of the grate cover to define a groove or gap into which a distal end of the first coupling member is pivotably received when the grate cover is in the closed position. In this way, the connection between the first coupling member and the second coupling member function together as a hinge-type joint.
Located in a transverse direction opposite to the coupling mechanism is an alignment mechanism for aligning the grate cover with respect to the base conduit when placing the grate cover in the closed position. The alignment mechanism includes an alignment bar formed at the lower surface of the grate cover at a position opposite to the second coupling member and an alignment bar formed at the upper end of the sidewall for engaging the alignment bar when the grate cover is in the closed position.
In a second embodiment, the modular trench drain system includes a coupling mechanism having an upper coupling member and a lower coupling member each formed at the upper end of one sidewall. A second coupling includes an extension arm which is offset downwardly from the upper surface of the grate cover body and a shoulder which projects substantially perpendicularly from the extension arm. The upper coupling member is spaced from the lower coupling member to define a groove or gap into which the second coupling member is pivotably received when the grate cover is in the closed position. The system of the second embodiment includes an alignment mechanism. An alignment mechanism including an alignment bar is provided for aligning the grate cover with respect to the base conduit when placing the grate cover in the closed position. The alignment bar is provided with a contact surface adapted to contact an upper flange member when the grate cover is in the closed position is provided.
In a third embodiment, the system includes symmetrical coupling mechanisms for pivotably securing the grate cover to the base conduit when the grate cover is in the closed position. The coupling mechanisms include a pair of first coupling members formed at the upper end of the sidewalls, respectively, and a pair of second coupling members formed on the lower surface of the grate cover body and adapted to pivotably engage the first coupling members, respectively, when the grate cover is in the closed position. The first coupling members each include an elongated flange that projects substantially perpendicularly from a respective sidewall while the second coupling members each include an elongated shaft having a projection which is spaced from the lower surface to define a groove or gap into which the first coupling members are pivotably received, respectively, when the grate cover is in the closed position. In this way, the connection between the first coupling members and the second coupling members function together as hinge-type joint.
A fourth embodiment of the invention includes a drain system that provides additional protection against expansion and/or contraction of a surrounding natural surface or pavement area that may adversely effect the connection between the grate cover and the base conduit. The modular trench drain system includes a base conduit having a lower wall and a pair of opposing sidewalls with vertical extensions which protect the outer side surfaces of the grate cover from the effects of expansion and/or contraction of a surrounding natural surface or pavement. Accordingly, the vertical extensions absorb the forces associated with the expansion and/or contraction of the surrounding natural surface or pavement area.
Each embodiment may be provided with additional coupling mechanisms for mechanically locking or securing the grate cover to the base conduit. These coupling mechanisms include a plurality of fasteners such as screws, bolts or the like which are rotateably secured into pre-drilled or pre-threaded bores that extend throughout the base conduit and the grate cover. The combination of the coupling mechanisms and the alignment mechanism function to prevent the unintentional, unauthorized or accidental vertical and longitudinal displacement of the grate cover with respect to the base conduit once the grate cover is in the closed position. They also function to allow easy access to the interior of the base conduit to perform maintenance on the drain system.
Moreover, various fittings, such as universal Tee or universal cross connectors, end adapters, end plugs and the like may be provided to facilitate on site installation of the trench drain system. In order to interconnect a plurality of axially-aligned modular trench drain assemblies, a connector member is provided to establish an elongated channel of indefinite length and devoid of any structural breaks or seals. The connector member may include a gasket member that provides a mechanical seal between assemblies.
The present invention will now be further described by reference to the following drawings.